The First Rule of the Underworld

No crossing is without cost.

Every threshold taken, every boundary broken, every descent accepted demands something in return.

Not always blood.
Not always flesh.
Sometimes memory.
Sometimes certainty.
Sometimes a portion of the soul too small to notice at first, and too vital to recover once it is gone.

This is one of the first truths beneath A Lightless Soul and the world of the Underworld series: nothing is entered freely.

The Underworld is not chaos. It is not randomness. It is not evil in the simple way people often imagine darkness to be.

It is structure.
It is consequence.
It is exchange.

What is taken is taken in balance.
What is given is rarely understood in the moment it is offered.
And what follows a crossing may begin long before the one who crossed realizes that anything has changed.

Some doors do not open all at once.
Some descents begin with grief.
Some begin with longing.
Some begin with the simple human need to hear one voice again.

And once a threshold has recognized you, it does not always forget.

This is the first rule of the Underworld:

No crossing is without cost.